The pros and cons of having a second dog

[insanityscatching]

We have loved and are loving every minute of having Eric in our family and would like to have a second at some point in the future. What I'd like to know are the pros and cons?
When would be the best time? Dog or bitch? Same or different breed entirely? Bigger or smaller? Have obviously factored in cost implications but are there others?

We got a second puppy and it was a struggle to begin with. Our first dog was an adult rescue (18 months), we got our second as a puppy 2 years later. First was a dog, the second a bitch.

So in between all the puppy training we also had to keep them separate, calm and happy, and walking two dogs isn't as easy as one (at first).

It wasn't easy, particularly as she started to get bigger and they fought. We went to a dog psychologist (yes they exist), and the problems we caused by us trying to enforce a system (oldest dog first), that just didn't work for them.

Once that was sorted they were a comfort and companion for one another. The youngest passed away 6 months after our old boy, and I swear she died of a broken heart.